The present invention relates to new a head phone design. More particularly, the invention concerns a head phone with support means for one or two loudspeaker units, and the loudspeaker unit or units is/are of the type resting on the outside of the user""s ear/ears.
Head phones are previously known in various embodiments, both with regard to transducer principle (e.g. dynamic types, electrostatic types), with regard to attachment means (e.g. head bow, self-supporting ear plug) and with regard to type of acoustical coupling to the user""s ear (e.g. closed type, open type, ear plug type).
The present application deals substantially with the last mentioned field, that is the acoustical coupling manner from the sound transducer to the user""s auditory canal.
Particularly within the field of auscultation, and specially in electronic auscultation using an amplified presentation of sounds picked up from e.g. a human body, it is important to use a light and comfortable head phone that is nevertheless capable of good transmission of a complete frequency range. In this connection low frequencies are of interest, but it is a disadvantage to have to rely on particularly heavy and large loudspeaker transducers.
A xe2x80x9cdouble actionxe2x80x9d head phone is previously known from U.S. Pat. No. 5,333,206, in which head phone there is arranged, in addition to an xe2x80x9cordinarilyxe2x80x9d arranged loudspeaker element for open engagement on the outside of the user""s ear, a small supplementary element extending somewhat into the auditory canal, to produce treble frequencies therein. For the rest, this design is however of a traditional outside and open type, and it needs relatively large transducers to provide a good bass response.
The present invention aims at providing good coupling of particularly the lower frequencies into the auditory canal from a conventionally supported head phone that may be of markedly light type.
Thus, in accordance with the invention there is provided a head phone comprising at least one, preferably two loudspeaker units of the type resting on the outside of the user""s ear, as well as a support means for the loudspeaker unit, e.g. a head bow. The head phone in accordance with the invention is characterised in that each loudspeaker unit is equipped on its sound transmission side with a sound concentrating duct arranged to be placed a short distance into the auditory canal when in use.
In a favourable embodiment of the head phone in accordance with the invention, the sound concentrating duct is made at least partly of a flexible material, for adaptation to the user""s ear.
The sound-concentrating duct may be provided with an elastic sealing material for sealing against the edge of the auditory canal.
In a favourable embodiment the sound-concentrating duct is substantially funnel-shaped, attached around the sound producing area of the loudspeaker unit and tapered in toward the user""s ear.
In a further favourable embodiment, the loudspeaker units may be pivotably mounted on the support means, for adaptation to the user in question.
Besides, in a favourable embodiment the sound concentrating duct may be equipped, near the sound transmission side of the loudspeaker unit, with a ball joint for adapting the angle of the sound concentrating duct toward the ear of the particular user.
In another aspect of the invention, there is provided an electronic stethoscope comprising a sound sensor unit for picking up body sounds and converting such sounds into electrical signals, an amplifying and processing unit for these signals, as well as a head phone that comprises at least one, preferably two loudspeaker units of the type that rests on the outside of the user""s ear(s) and a support means for the loudspeaker unit(s), e.g. a head bow. The stethoscope in accordance with the invention is characterised in that each loudspeaker unit is equipped with a sound-concentrating duct on its sound transmission side, arranged to be placed a short distance into the auditory canal when in use.